The invention relates to highly conductive resinous compositions containing a resinous material and a finely divided conductive solid and to electroconductive articles employing such compositions.
Conductive resinous compositions, i.e., compositions formulated from a resinous binder material which has been filled with particulates of conductive materials such as carbon black, metals such as copper and silver, and the like have been widely used as electrical cable jacketings, electrical resistors, in heating elements and printed circuits as electrodes for capacitors, as conductive adhesives and so forth. See, for example, U.S. Pat. Nos. 3,412,358, 3,056,750, 3,359,145, and 2,165,738 and 3,185,907.
Unfortunately, in order to achieve even moderate degrees of conductivity, i.e., resistances less than one ohm-cm, required in many applications, it has been necessary to incorporate as much as 75 weight percent of the conductive particulate based on the resinous binder. At such levels of the conductive filler, the ease of fabrication and the overall strength of the conductive composition are often reduced to the point that they are either not acceptable or are marginally so for the intended use. Some high degrees of conductivity, i.e., less than 0.1 ohm-cm, cannot be practically achieved by conventional incorporation of a conductive particulate into a resinous binder.
Therefore, it would be highly desirable to provide a resinous composition having moderate or high degrees of conductivity at levels of conductive particulate much lower than those required in prior art conductive compositions.